When both fast action and quality results are important, 3M™ Fast N Firm Seam Sealer is a preferred choice. this firm setting product can seal a variety of external automotive joints and seams. With its high solids and low shrinkage properties, our sealer provides predictable and reliable results. Youll have a work time ranging from 5 to 10 minutes. It quickly skins and cures quickly. In fact, it cures so quickly that you can often paint in as few as 45 minutes, so there is less downtime in waiting for the sealer to fully cure.